Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus.

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Combined paralysis of the abducens and facial nerves following idiopathic intracranial hypertension.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a clinical phenomenon that reflects an increase in intracranial pressure in the brain with normal parenchyma and no signs of ventriculomegaly, malignancy, infection, or any space-occupying lesion. Generally, this disease is associated with symptoms such as headache, transient visual obscurations (unilateral or bilateral darkening of the vision typically seconds), intracranial noise, diplopia, blurring of vision, abducens nerve palsies, and unilateral or bilateral facial nerve paresis (which is a very rare complication of this disease that has been reported in some studies). CASE PRESENTATION: An 8-year-old boy with a history of bilateral frontal headache for 2 weeks, right ear pain, vomiting, and intermittent fever, who had received antibiotics and analgesics with improvement of ear pain and continuation of headache, presented to this center. In the initial neurological examinations, bilateral papilledema and right-sided 6th and 7th cranial nerve palsy (peripheral) were observed. After performing LP and CT scan and MRV for the patient, a diagnosis of pseudotumor cerebri was made and he was treated with acetazolamide, prednisolone, and topiramate. He was discharged after 10 days. CONCLUSION: Although pseudotumor cerebri is less common in children than adults and obesity and female gender are considered as risk factors for this disease, it is not usually associated with involvement of the 6th and 7th cranial nerves. However, sometimes this disease can occur in children without any risk factors and with less common involvement of the 6th and 7th cranial nerves.

Paediatric idiopathic intracranial hypertension: Epidemiology, clinical features and treatment outcomes in a tertiary care centre in Western Australia.

AIM: This retrospective study aims to analyse the epidemiology, clinical and neuroimaging features, treatment modalities, and outcomes of paediatric idiopathic intracranial hypertension (IIH) in a tertiary care centre in Australia. METHODS: Using the International Classification of Diseases Diagnostic Criteria for IIH, we identified and analysed a cohort of children diagnosed with IIH over a 5-year period (2017-2022). Data on patient demographics, symptomatology, examination findings, investigative results, treatments and outcomes were collected from medical records and electronic health records. RESULTS: A total of 45 cases were analysed. The pre-pubertal group saw a male predominance and the post-pubertal a female one. Increased body mass index was an associated comorbidity in majority of patients. Headaches (89%) and visual symptoms (56%) were the most common symptoms, with tinnitus also seen in 20% of patients. Papilledema was detected in 91% of the cases examined. The commonest neuroimaging features were optic nerve sheath distention (78%) and empty sella (49%). Acetazolamide was the primary treatment, with most patients responding well. Only a minority required surgical intervention. Long-term resolution of headaches was achieved in 89% of patients. CONCLUSIONS: The incidence of paediatric IIH in the West Australian population appears relatively high. It presents with subtle symptoms, emphasising the need for increased awareness among health-care providers. Younger children may represent a distinct subgroup with unique clinical features. Timely diagnosis and aggressive medical management lead to favourable outcomes. However, weight loss interventions showed limited effectiveness. This study underscores the importance of early recognition and management of paediatric IIH to optimise patient outcomes.

Is there evidence for the(sole) use of third ventriculostomy in the treatment of Idiopathic. Intracranial Hypertension: A Literature Review.

BACKGROUND: Idiopathic intracranial hypertension (IIH) remains a poorly understood condition with no standardised treatment. Treatment is therefore generally individualised. Recent isolated reports have begun to describe the use of third ventriculostomy (open or closed) for the treatment of IIH. This review aims to communicate the current evidence for the use of third ventriculostomy in IIH. METHODS: A systemic review, using PubMed, was performed of studies describing the use of third ventriculostomy, either open or closed, for the treatment of idiopathic intracranial hypertension. RESULTS: Only 3 studies for a total of 3 patients were found in which a third ventriculostomy was performed for the treatment of IIH. CONCLUSION: Despite very plausible proposed mechanisms of action, there is currently a paucity of both studies and, therefore, evidence for the use of either endoscopic or open third ventriculostomy for the treatment of IIH. The studies done to date do strongly suggest that further consideration is warranted.

Predictors of Headaches and Quality of Life in Women with Ophthalmologically Resolved Idiopathic Intracranial Hypertension.

Background/objectives: The aim of this study was to evaluate the long-term outcomes of a cohort of ophthalmologically resolved female idiopathic intracranial hypertension (IIH) patients. Methods: Our cross-sectional study included adult females with at least 6 months of ophthalmologically resolved IIH. Patients with papilledema or who underwent IIH-targeted surgical intervention were excluded. Participants completed a questionnaire consisting of medical information, the Migraine Disability Assessment Scale (MIDAS) and the Headache Impact Test (HIT-6). Electronic medical records and the results of imaging upon diagnosis were retrospectively reviewed. Results: One-hundred-and-four participants (mean age 35.5 ± 11.9 years) were included (7.85 ± 7 years post-IIH diagnosis). Patients with moderate-severe disability according to the MIDAS scale (n = 68, 65.4%) were younger (32.4 ± 8.9 vs. 41.5 ± 14.4 year-old, p < 0.001), had a shorter time interval from IIH diagnosis (5.9 ± 5.3 vs. 11.7 ± 8.5 years, p < 0.001), and had lower FARB scores (indicating a more narrowed transverse-sigmoid junction; 1.28 ± 1.82 vs. 2.47 ± 2.3, p = 0.02) in comparison to patients with low-mild disability scores. In multivariate analysis, a lower FARB score (OR 1.28, 95% CI 0.89-1.75, p = 0.12) and younger age (OR 1.09, 95% CI 0.98-1.19, p = 0.13) showed a trend toward an association with a moderate-severe MIDAS score. Moreover, in the sub-analysis of patients with a moderate-severe MIDAS scale score, the 10 patients with the highest MIDAS scores had a low FARB score (1.6 ± 1.1 vs. 2.7 ± 2.4, p = 0.041). Conclusions: High numbers of patients with ophthalmologically resolved IIH continue to suffer from related symptoms. Symptoms may be associated with the length of time from the diagnosis of IIH and a lower FARB score.

A Case Report of Idiopathic Intracranial Hypertension With Left-Sided Facial Spasm.

Idiopathic intracranial hypertension (IIH) typically presents with increased intracranial pressure of an unknown origin. Facial spasms are an uncommon manifestation of IIH. We report a 56-year-old female patient displaying atypical IIH symptoms of left-sided facial spasm. Clinical examination and imaging confirmed the diagnosis of IIH, and the patient received treatment with acetazolamide. This case highlights the importance of considering IIH as a potential diagnosis in patients with facial spasms, especially when accompanied by other neurological symptoms. Early recognition, a high level of suspicion, and appropriate management are crucial for optimizing outcomes in IIH cases. Furthermore, collaboration among neurologists, neurosurgeons, radiologists, and ophthalmologists is essential for the comprehensive evaluation and management of IIH patients.

A Case of Idiopathic Intracranial Hypertension Complicated with both Infratentorial and Supratentorial Cortical Superficial Siderosis: Novel Imaging Findings on Intravoxel Incoherent Motion Magnetic Resonance Imaging Offering Clues to Pathophysiology.

The pathology of idiopathic intracranial hypertension (IIH), a disease characterized by papillary edema and increased intracranial pressure (IICP), is not yet understood; this disease significantly affects quality of life due to symptoms including vision loss, headache, and pulsatile tinnitus. By contrast, superficial siderosis (SS), a disorder in which hemosiderin is deposited on the surface of the cerebral cortex and cerebellum, potentially causes cerebellar ataxia or hearing loss. So far, no cases of IIH with infratentorial and supratentorial cortical SS have been reported. Herein, we report a case of a 31-year-old woman with obesity who developed this condition. The patient suddenly developed headache and dizziness, had difficulty walking, and subsequently became aware of diplopia. Fundus examination revealed bilateral optic nerve congestive papillae and right eye abducens disturbance. Head magnetic resonance imaging (MRI) showed prominent SS on the cerebellar surface and cerebral cortex. Lumbar puncture revealed IICP of 32 cmH2O, consistent with the diagnostic criteria for IIH, and treatment with oral acetazolamide was started; subsequently, the intracranial pressure decreased to 20 cmH2O. Her abduction disorder disappeared, and the swelling of the optic papilla improved. She was now able return to her life as a teacher without any sequelae. SS is caused by persistent slight hemorrhage into the subarachnoid space. In this case, both infratentorial and supratentorial cortical superficial SS was observed. Although cases of IIH complicated by SS are rare, it should be kept in mind that a causal relationship between IIH and SS was inferred from our case. Our findings also suggest that cerebrospinal fluid dynamic analysis using MRI is effective in diagnosing IIH and in determining the efficacy of treatment.

Application of novel non-invasive ophthalmic imaging to visualize peripapillary wrinkles, retinal folds and peripapillary hyperreflective ovoid mass-like structures associated with elevated intracranial pressure.

Background: Elevated intracranial pressure (ICP) is a serious and potentially life-threatening condition, for which clinically useful non-invasive measures have been elusive, in some cases due to their inadequate sensitivity and specificity. Our aim was to evaluate novel non-invasive ophthalmic imaging of selected pathological features seen in elevated ICP, namely peripapillary hyperreflective ovoid mass-like structures (PHOMS), peripapillary wrinkles (PPW) and retinal folds (RF) as potential biomarkers of elevated ICP. Methods: This single-center pilot study included subjects with untreated or incompletely treated high ICP. The retinas of these subjects were evaluated with averaged en-face optical coherence tomography (OCT), OCT retinal cross-sections (OCT B-scans), adaptive optics scanning light ophthalmoscopy (AOSLO), and fundus photos. Results: Seven subjects were included in the study. 6 subjects with high ICP (5 idiopathic intracranial hypertension, 1 medication induced, 30.8 ± 8.6 years, 75% female, 5 with papilledema) and 1 control (20-25 years) were included. PHOMS, PPW and RF were present in all subjects with papilledema, but neither in the high ICP subject without papilledema nor in the control subject. Averaged en-face OCT scans and AOSLO were more sensitive for PPW and RF than OCT B-scans and commercial fundus photos. Conclusion: PPW, RF and PHOMS volume have potential as non-invasive biomarkers of ICP. Novel imaging modalities may improve sensitivity. However, lack of automated image acquisition and processing limits current widespread adoption in clinical settings. Further research is needed to validate these structures as biomarkers for elevated ICP and improve clinical utility.

Is foramen magnum decompression for acquired Chiari I malformation like putting a finger in the dyke? - A simplistic overview of artificial intelligence in assessing critical upstream and downstream etiologies.

Background: Missed diagnosis of evolving or coexisting idiopathic (IIH) and spontaneous intracranial hypotension (SIH) is often the reason for persistent or worsening symptoms after foramen magnum decompression for Chiari malformation (CM) I. We explore the role of artificial intelligence (AI)/convolutional neural networks (CNN) in Chiari I malformation in a combinatorial role for the first time in literature, exploring both upstream and downstream magnetic resonance findings as initial screening profilers in CM-1. We have also put together a review of all existing subtypes of CM and discuss the role of upright (gravity-aided) magnetic resonance imaging (MRI) in evaluating equivocal tonsillar descent on a lying-down MRI. We have formulated a workflow algorithm MaChiP 1.0 (Manjila Chiari Protocol 1.0) using upstream and downstream profilers, that cause de novo or worsening Chiari I malformation, which we plan to implement using AI. Materials and Methods: The PRISMA guidelines were used for "CM and machine learning and CNN" on PubMed database articles, and four articles specific to the topic were encountered. The radiologic criteria for IIH and SIH were applied from neurosurgical literature, and they were applied between primary and secondary (acquired) Chiari I malformations. An upstream etiology such as IIH or SIH and an isolated downstream etiology in the spine were characterized using the existing body of literature. We propose the utility of using four selected criteria for IIH and SIH each, over MRI T2 images of the brain and spine, predominantly sagittal sequences in upstream etiology in the brain and multiplanar MRI in spinal lesions. Results: Using MaChiP 1.0 (patent/ copyright pending) concepts, we have proposed the upstream and downstream profilers implicated in progressive Chiari I malformation. The upstream profilers included findings of brain sagging, slope of the third ventricular floor, pontomesencephalic angle, mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter, clivus length, tonsillar descent, etc., suggestive of SIH. The IIH features noted in upstream pathologies were posterior flattening of globe of the eye, partial empty sella, optic nerve sheath distortion, and optic nerve tortuosity in MRI. The downstream etiologies involved spinal cerebrospinal fluid (CSF) leak from dural tear, meningeal diverticula, CSF-venous fistulae, etc. Conclusion: AI would help offer predictive analysis along the spectrum of upstream and downstream etiologies, ensuring safety and efficacy in treating secondary (acquired) Chiari I malformation, especially with coexisting IIH and SIH. The MaChiP 1.0 algorithm can help document worsening of a previously diagnosed CM-1 and find the exact etiology of a secondary CM-I. However, the role of posterior fossa morphometry and cine-flow MRI data for intracranial CSF flow dynamics, along with advanced spinal CSF studies using dynamic myelo-CT scanning in the formation of secondary CM-I is still being evaluated.

Atypical Presentation of Idiopathic Intracranial Hypertension: A Case Series and Literature Review.

Idiopathic intracranial hypertension (IIH) is a condition in which intracranial pressure (ICP) increases without an apparent cause. Typically, patients present with headaches, dizziness, pulsatile tinnitus, visual disturbances, blurred vision, diplopia, photophobia, visual field defects, and papilledema on fundoscopy. The association between IIH, spontaneous cerebrospinal fluid (CSF) rhinorrhea, and arachnoid cysts has been discussed in the literature; however, there is no clear explanation for this association. We aimed to present a series of four patients with a confirmed diagnosis of IIH with atypical presentations, discuss the management of each case, and provide an explanation for this association to alert clinicians to the atypical presentation of IIH and facilitate early diagnosis and proper treatment of this condition by CSF diversion. This was a retrospective case series of all patients who were diagnosed with IIH and showed improvement after ventriculoperitoneal shunt insertion after failure of at least one operative intervention resulting from primary radiological and clinical findings in 2001 to 2022. Data on demographics, clinical presentation, radiological findings, surgical management, and diagnostic criteria for IIH were recorded. We identified four patients with a confirmed diagnosis of IIH who presented with atypical presentations as follows: intracranial arachnoid cyst, cervical spine arachnoid cyst, giant Virchow perivascular space, and spontaneous CSF (CSF) rhinorrhea. All patients responded to CSF diversion after failure of surgical treatment targeting the primary pathology. IIH should be suspected after the failure of primary surgical treatment in cases of spontaneous CSF rhinorrhea, spinal and cranial arachnoid cysts, and symptomatic ventriculoperitoneal shunt. Treatment in such situations should be directed toward IIH with CSF diversion.

Clinical characteristics and surgical outcomes of epilepsy associated with temporal encephalocele: A systematic review.

Temporal encephaloceles (TE) are an under-identified, potentially intervenable cause of epilepsy. This systematic review consolidates the current data to identify the major clinical, neuroimaging, and EEG features and surgical outcomes of epilepsy associated with TE. Literature searches were carried out using MEDLINE, Embase, PsycINFO, Scopus, and Cochrane Library databases from inception to December 7, 2023. Studies were included if they described clinical, neuroimaging, EEG, or surgical data in ≥5 patients with TE and epilepsy. Of 562 studies identified in the search, 24 met the eligibility criteria, reporting 423 unique patients with both epilepsy and TE. Compared to epilepsy patients without TE, those with TE had a higher mean age of seizure onset and were less likely to have a history of febrile seizures. Seizure semiologies were variable, but primarily mirrored temporal lobe onset patterns. Epilepsy patients with TE had a higher likelihood of having clinical or radiographic features of idiopathic intracranial hypertension (IIH) than those without. Brain MRI may show ipsilateral mesial temporal sclerosis (16 %). CT scans of the skull base usually revealed bony defects near the TE (90 %). Brain PET scans primarily showed ipsilateral temporal lobe hypometabolism (80 %), mostly in the anterior temporal lobe (67 %). Scalp EEG mostly lateralized ipsilateral to the implicated TE (92 % seizure onset) and localized to the temporal lobe (96 %). Intracranial EEG revealed seizure onset near the TE (11 of 12 cases including TE-adjacent electrodes) with variable timing of spread to the ipsilateral hippocampus. After surgical treatment of the TE, the rate of Engel I or ILAE 1 outcomes at one year was 75 % for lesionectomy, 85 % for anterior temporal lobectomy (ATL), and 80 % for ATL with amygdalohippocampectomy. Further studies are needed to better elucidate the relationship between IIH, TE, and epilepsy, improve the identification of TE, and optimize surgical interventions.

Plasma calcitonin gene-related peptide levels in idiopathic intracranial hypertension: an exploratory study.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a debilitating condition characterized by increased intracranial pressure often presenting with chronic migraine-like headache. Calcitonin gene-related peptide (CGRP) plays an important pathophysiological role in primary headaches such as migraine, whilst its role in IIH has not yet been established. METHODS: This longitudinal exploratory study included patients with IIH, episodic migraine (EM) in a headache-free interval and healthy controls (HC). Blood samples were collected from a cubital vein and plasma CGRP (pCGRP) levels were measured by standardized ELISA. RESULTS: A total of 26 patients with IIH (mean age 33.2 years [SD 9.2], 88.5% female, median BMI 34.8 kg/m2 [IQR 30.0-41.4]), 30 patients with EM (mean age 27.6 years [7.5], 66.7% female) and 57 HC (mean age 25.3 years [5.2], 56.1% female) were included. pCGRP levels displayed a wide variation in IIH as well as in EM and HC on a group-level. Within IIH, those with migraine-like headache had significantly higher pCGRP levels than those with non-migraine-like headache (F(2,524) = 84.79; p < 0.001) and headache absence (F(2,524) = 84.79; p < 0.001) throughout the observation period, explaining 14.7% of the variance in pCGRP levels. CGRP measurements showed strong intraindividual agreement in IIH (ICC 0.993, 95% CI 0.987-0.996, p < 0.001). No association was found between pCGRP levels and ophthalmological parameters. CONCLUSIONS: Although interindividual heterogeneity of pCGRP levels is generally high, migraine-like headache seems to be associated with higher pCGRP levels. CGRP may play a role in the headache pathophysiology at least in a subgroup of IIH.

Exploring the utility of retinal optical coherence tomography as a biomarker for idiopathic intracranial hypertension: a systematic review.

This study aimed to examine the existing literature that investigated the effectiveness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) as a biomarker for idiopathic intracranial hypertension (IIH). Our search was conducted on January 17th, 2024, and included the databases, Medline, Scopus, Embase, Cochrane, Latin American and Caribbean Health Sciences Literature (LILACS), International Standard Randomized Controlled Trial Number (ISRCTN) registry, and the International Clinical Trials Registry Platform (ICTRP). Our final review included 84 articles. In 74 studies, OCT was utilized as the primary ocular imaging method, while OCT-A was employed in two studies including eight studies that utilized both modalities. Overall, the results indicated that IIH patients exhibited significant increases in retinal nerve fiber layer (RNFL) thickness, total retinal and macular thickness, optic nerve head volume, and height, optic disc diameter and area, rim area, and thickness compared to controls. A significant correlation was observed between cerebrospinal fluid (CSF) pressure and OCT parameters including RNFL thickness, total retinal thickness, macular thickness, optic nerve head volume, and optic nerve head height. Interventions aimed at lowering CSF pressure were associated with a substantial improvement in these parameters. Nevertheless, studies comparing peripapillary vessel density using OCT-A between IIH patients and controls yielded conflicting results. Our systematic review supports OCT as a powerful tool to accurately monitor retinal axonal and optic nerve head changes in patients with IIH. Future research is required to determine the utility of OCT-A in IIH.

Role of neuroimaging markers on predicting of idiopathic intracranial hypertension.

BACKGROUND: The goals of neuroimaging in idiopathic intracranial hypertension (IIH) are the exclusion of mimickers and effective management of disease. In recent studies, several imaging markers have been identified as potential predictors of IIH. PURPOSE: To investigate the predictive roles of novel radiological markers as the Meckel's cave area, alongside classical radiologic markers in identifying IIH such as the empty sella. MATERIAL AND METHODS: The patients were classified according to cerebrospinal fluid (CSF) opening pressure as the IIH group and control group. The observational, case-control study included 22 patients with IIH and 22 controls. Groups were compared for presence of empty sella, Meckel's cave area, fat area of posterior neck, fat thickness of scalp, presence of transverse sinus stenosis, and ophthalmic markers, such as increase of optic nerve (ON) sheath diameter. RESULTS: In the IHH group, higher occurrences of increased ON sheath diameter, ON tortuosity, flattening of the scleral surface, and transverse sinus stenosis were observed (P < 0.001, P < 0.001, P = 0.046, and P = 0.021, respectively). Meckel's cave area and fat area of posterior neck were similar in both groups (P = 0.444 and P = 0.794). CONCLUSION: Ophthalmic markers and transverse sinus stenosis could be utilized as radiologic features supporting early and precise diagnosis of IIH. However, enlargement of Meckel's cave area and measurements of fatty area of posterior neck are not helpful for diagnosis of IIH.

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management.

PURPOSE OF REVIEW: The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus. RECENT FINDINGS: Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

Arachnoid granulations in idiopathic intracranial hypertension: Do they have an influence?

OBJECTIVE: The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with idiopathic intracranial hypertension (IIH) compared to healthy controls. BACKGROUND: IIH is characterized by increased intracranial pressure, which is associated with symptoms such as headache and visual disturbances. The role of cerebral venous drainage obstruction in IIH is the subject of ongoing research. MATERIALS AND METHODS: In this retrospective case-control study, 3D contrast-enhanced magnetic resonance images of a cohort of 43 patients with IIH were evaluated for (1) the number of AGs per venous sinus and (2) the diameters of the dural venous sinuses at the site of an AG and at standardized measurement points. In addition, the minimum width of the transverse/sigmoid sinus was measured. All data were compared to the same data from a cohort of 43 control participants. RESULTS: Patients with IIH showed less relative sinus narrowing by AG compared to controls (median: 7%, interquartile range [IQR] 10% vs. 11%, IQR 9% in controls; p = 0.009). In patients with IIH, sinus diameter was larger at the site of an AG (70 ± 25 mm2) compared to its diameter at the standardized measurement point (48 ± 23 mm2; p = 0.010). In the superior sagittal sinus (SSS), patients with IIH had smaller AGs (median: 3 mm2, IQR 2 mm2 vs. 5 mm2, IQR 3 mm2 in controls; p = 0.023) while the respective sinus segment was larger (median: 69 mm2; IQR 21 mm2 vs. 52 mm2, IQR 26 mm2 in controls; p = 0.002). The right transverse sinus was narrower in patients with IIH (41 ± 21 mm vs. 57 ± 20 mm in controls; p < 0.001). CONCLUSIONS: In contrast to our hypothesis, patients with IIH showed less pronounced relative sinus narrowing by AG compared to controls, especially within the SSS, where AGs were smaller and the corresponding sinus segment wider. Smaller AGs could result in lower cerebrospinal fluid resorption, favoring the development of IIH. Conversely, the smaller AGs could also be a consequence of IIH due to backpressure in the SSS because of the narrower transverse/sigmoid sinus, which widens the SSS and compresses the AG.

Idiopathic Intracranial Hypertension in an Adolescent With Recent Human Immunodeficiency Virus (HIV) Diagnosis: A Challenging Etiological Dilemma.

Idiopathic intracranial hypertension (IIH) or benign intracranial hypertension affects the neuro-ophthalmological system and leads to elevated intracranial pressure. Elevated opening pressure during lumbar puncture is diagnostic of IIH. Here in, we present an interesting case of a 15-year-old girl, recently immigrated and with a high BMI, presenting with recurrent fever, abdominal issues, weight loss, and other symptoms, leading to a diagnosis of pelvic inflammatory disease (PID) and HIV infection. After treatment with antibiotics (doxycycline) and antiretroviral therapy, she developed IIH, manifesting as sudden-onset headache and vision problems. MRI and lumbar puncture confirmed the diagnosis. She responded well to acetazolamide and was discharged with continued medication and follow-up appointments. This case underscores the complexity of IIH development, especially in the setting of acute HIV infection and antibiotic treatment, highlighting the need for a comprehensive diagnostic approach and multidisciplinary management.

Vaulting further: cranial vault expansion for craniocerebral disproportion without primary craniosynostosis.

PURPOSE: Treatment of subjects with refractory idiopathic intracranial hypertension (IIH) or shunted hydrocephalus with chronic shunt complications is challenging. What is the role for cranial vault expansion, particularly utilizing posterior vault distraction osteogenesis (PVDO), in these cases? This study assesses medium-term efficacy of cranial vault expansion in this unique patient population. METHODS: A retrospective review was conducted of patients who underwent cranial vault expansion from 2008 to 2023 at the Children's Hospital of Philadelphia. Subjects who did not have a diagnosis of primary craniosynostosis were included in the study. Demographic information, medical history, and perioperative details were collected from medical records. Primary outcomes were the rate of CSF diversion procedures and resolution of presenting signs and symptoms. Secondary outcomes were perioperative and 90-day complications and reoperation requirement. RESULTS: Among 13 included subjects, nine (69.2%) patients had a primary diagnosis of shunted hydrocephalus and 4 (30.8%) patients had IIH. Twelve (92.3%) subjects underwent posterior vault distraction osteogenesis (PVDO) and one (7.7%) underwent posterior vault remodeling (PVR). All 4 patients with IIH demonstrated symptomatic improvement following PVDO, including resolution of headaches, vomiting, and/or papilledema. Among 9 patients with shunted hydrocephalus, CSF diversion requirement decreased from 2.7 ± 1.6 procedures per year preoperatively to 1.2 ± 1.8 per year following cranial vault expansion (p = 0.030). The mean postoperative follow-up was 4.1 ± 2.1 years and four (30.8%) patients experienced complications within 90 days of surgery, including infection (n = 2), CSF leak (n = 1), and elevated ICP requiring lumbar puncture (n = 1). Four (30.8%) patients underwent repeat cranial vault expansion for recurrence of ICP-related symptoms. At most recent follow-up, 7 of 9 patients with shunted hydrocephalus demonstrated symptomatic improvement. CONCLUSION: Cranial vault expansion reduced intracranial hypertension-related symptomology as well as the rate of CSF diversion-related procedures in patients with refractory IIH and shunted hydrocephalus without craniosynostosis, and should be considered in those who have significant shunt morbidity.

NeuroBehcet's-related intracranial hypertension without cerebral venous thrombosis: case report and review of literature.

BACKGROUND: We present a rare case of NeuroBehcet's-related intracranial hypertension without cerebral venous thrombosis (NBrIHwCVT), occurring as the first presentation of NeuroBehcet's. In addition, we describe the novel use of subcutaneous tocilizumab for this indication. This is followed by a review of the literature on this topic. CASE: The patient was a 28-year-old lady of Southern Chinese origin with a known history of Behcet's disease with oral ulcers and ocular findings for which she was on mycophenolate mofetil and adalimumab. She presented with a headache and bilateral disc swelling associated with an intracranial pressure (ICP) of > 40cmH20. There were no structural lesions or cerebral venous thrombosis (CVT) on imaging. Initial lumbar puncture had raised leucocytes and protein. We discuss diagnostic challenges given persistently elevated ICP despite subsequent non-inflammatory cerebrospinal fluid (CSF) profiles and non-response to acetazolamide. She eventually showed a response to immunosuppressant therapy in the form of pulsed methylprednisolone, cyclophosphamide and subsequently subcutaneous tocilizumab, supporting the diagnosis of NBrIHwCVT. Complete normalization of ICP remains challenging. Her disease course was severe, unusual for her ethnicity. LITERATURE REVIEW: We identified 34 patients (including ours) from 14 publications. We found that the majority of NBrIHwCVT patients were young (average age of 34 years), with a slight female preponderance. Of the 17 cases in the literature with available data on CSF profile, none had raised leucocytes whilst one patient had elevated protein. Patients were generally treated with steroids and occasionally azathioprine, in line with the suspected autoimmune pathophysiology. Of 22 patients with data on outcome, six (27%) were noted to have recurrence of symptoms generally occurring a few months later. CONCLUSION: As demonstrated by this case, NBrIHwCVT can present with BD with raised ICP even if there is no prior history of NB, central Asian ethnicity, cerebral venous thrombosis or features of inflammation on the CSF. We demonstrated how novel use of Tocilizumab may have a role in the management of NBrIHwCVT. Based on our literature review, patients were more likely to be young, female, display a non-inflammatory CSF picture, be treated with steroids and harbour a possibility of recurrence.